Certain video systems have an optical sensor that transfers video frames to a camera core within a video circuit having a video coder/decoder (VCODEC) and a local memory. The video frames must pass from the camera core and eventually reach the VCODEC for coding and subsequent processing. However, the camera core cannot directly hand off the video frames to the VCODEC because the camera core and local memory lack sufficient storage capacity to function as a video frame buffer. The camera core also generally lacks required handshaking functions for passing video frames to the VCODEC. The video circuit therefore offloads entire video frames from the camera core to an external memory, then retrieves these offloaded video frames from the external memory and inputs the frames to the VCODEC. The offloading and retrieval of the video frames is generally controlled by an application processor. The external memory and the application processor, however, each consume considerable power.
Prior means and efforts to reduce, or offset, this power include placing the external memory and interfacing circuitry between the camera core and the external memory in closer proximity, as well as using higher burst length for the video frame transfers to increase bus efficiency. The prior means and efforts also include scaling of the bus and core clock. The prior means and efforts, although reducing power consumption, do not remove the power consumption by the external memory or by the application processor.